The WD40 domain-containing protein Ehd5 positively regulates flowering in rice (Oryza sativa)

• DOI: 10.1093/plcell/koad223
• Publication Date: 2023-08-31T00:28:50Z
• Authors: Xuening Zhang; Qi Feng; Jiashun Miao; Jingjie Zhu; Congcong Zhou; Danlin Fan; Yiqi Lu; Qilin Tian; Yongchun Wang; Qilin Zhan; Zi-Qun Wang; Ahong Wang; Lei Zhang; Yingying Shangguan; Wenjun Li; Jiaying Chen; Qijun Weng; Tao Huang; Shican Tang; Lizhen Si; Xuehui Huang; Zi-Xuan Wang; Bin Han
• Keywords: 2. Zero hunger; WD40 Repeats; Gene Expression Regulation, Plant; Photoperiod; Oryza; Flowers; Research Article; Circadian Rhythm; Plant Proteins

Abstract Heading date (flowering time), which greatly influences regional and seasonal adaptability in rice (Oryza sativa), is regulated by many genes in different photoperiod pathways. Here, we characterized a heading date gene, Early heading date 5 (Ehd5), using a modified bulked segregant analysis method. The ehd5 mutant showed late flowering under both short-day and long-day conditions, as well as reduced yield, compared to the wild type. Ehd5, which encodes a WD40 domain-containing protein, is induced by light and follows a circadian rhythm expression pattern. Transcriptome analysis revealed that Ehd5 acts upstream of the flowering genes Early heading date 1 (Ehd1), RICE FLOWERING LOCUS T 1 (RFT1), and Heading date 3a (Hd3a). Functional analysis showed that Ehd5 directly interacts with Rice outermost cell-specific gene 4 (Roc4) and Grain number, plant height, and heading date 8 (Ghd8), which might affect the formation of Ghd7–Ghd8 complexes, resulting in increased expression of Ehd1, Hd3a, and RFT1. In a nutshell, these results demonstrate that Ehd5 functions as a positive regulator of rice flowering and provide insight into the molecular mechanisms underlying heading date.